Ah, the thrill of plunging into a good movie with no prior knowledge. It’s rare, not simply because of the ubiquity of marketing material in the connected world, but also because said films don’t usually live up to the version imagined in one’s own mind. (Blade Runner 2049, please don’t ruin my android dreams!)

It Comes At Night is a dark, small-scale apocalyptic thriller that works best if all you know is that it’s a dark, small-scale apocalyptic thriller. It is taut, tense, brutal, scary, and filled with perfectly calibrated performances. Now, go see it.

Okay, if you must know more, here we go. The setting is sometime after some kind of apocalypse. An old man is dying. Paul (Joel Edgerton) takes him to the woods, shoots him, and then incinerates his body. Paul is father to Travis (Kelvin Harrison Jr) and husband to Sarah (Carmen Ejogo). They live in a big, boarded-up house in the woods. The old man was Travis’s grandfather, and they had to dispose of the body because out there, in the wilderness, some kind of contagion has destroyed society.

One night there’s a break-in. The culprit is Will (Christopher Abbott), a young man apparently in good health, yet desperate to bring water back to his wife and son. Paul and Will brave the highwaymen and travel to Will’s place to collect Kim (Riley Keogh) and Andrew (Griffin Robert Faulkner). The two families come together. The live together and work together in apparent harmony. But tragedy lurks just outside the Red Door. The tension ramps up as it becomes clear that both fathers will do whatever it takes to protect their own family.

It Comes At Night is dark. Seriously, it’s a Debbie Downer, folks. We’re talking unrelentingly bleak and crushing in its hopelessness. It’s also brilliantly made and utterly gripping. Part of a fine tradition of social breakdown movies, it can be found at the point where The Road meets The Village, just off 10 Cloverfield Lane.

The atmosphere is thick enough to chew, like air choked with something foul. It all comes down to Trey Edward Shults’ precision direction. For a start, he manages to capture the swallowing darkness of the woods at night. But more important is the way he frames the people inside their isolated fortress: faces illuminated by single light sources, glowing like islands in an uncertain darkness where the shape of familiar things cannot be apprehended. Like a family unfinished.

For a 90-minute movie where mood is the main character, the humans (the men, anyway – this is a film about masculinity) are astonishingly well-drawn. Edgerton, in particular, is superb in the role of the paranoid patriarch. His distrust is pathological, yet his ferocious defensiveness hides a tragic tenderness.

Then there’s Travis, the 17-year-old kid who might never have even seen a woman close to his age. His dreams are of people he loves or desires, and always they end in his wishes – to make love with Kim; to see his granddad again – being scarily, violently spoiled.

Travis’s waking dreams are the film’s overt horror element. Edward Shults has already laid the groundwork for a house invasion nightmare; and then when Travis goes for one of his sleepless strolls, we suddenly have the added tension and ambiguity of dream logic to contend with. This isn’t some dumb teen to be bumped off – in the hands of Harrison, Travis’s curiosity and vulnerability is heartbreaking.

As the tension mounts and guns are pointed, a key theme becomes clear: Security, at what price? It Comes At Night is a fable about protectionism. As lives uncomfortably intertwine, the secure family unit – the default ideal of many a modern horror – becomes something sinister; something that threatens to destroy, rather than repair, the remnants of a shattered society.

Proving that 2014’s Krisha was no accident, Trey Edward Shults’ obsidian dark sophomore feature is another triumph. Intense, meticulous and textured, it’s a horror movie that challenges the mind as much as the senses. Be warned, though: a date movie this ain’t.